1. Technical Field
The present disclosure relates to optical coating devices, and more specifically, to an adjustable mask for use in an optical coating process.
2. Description of Related Art
At present, optical film can be coated on surfaces of optical components through physical vapor deposition (PVD). Optical coating devices often include a vacuum room, an evaporation source, a substrate carrier arranged above the evaporation source, and a mask between the evaporation source and the substrate carrier. The mask is used for adjusting the thickness of the film deposited on the surface of the substrates on the different locations of the substrate carrier. For example, if the film on the surface of substrates on the outer portions of the substrate carrier is thicker than preset thickness, an aluminum foil can be used to extend the mask corresponding to the outer portions to shield the evaporation source more, such that less evaporation material will reach the outer portions. Although conventional masks can satisfy basic requirements, a new adjustable mask is still required.